In zoological anatomy, a cloaca /kloʊˈeɪkə/ is the posterior opening that serves as the only such opening for the intestinal, reproductive, and urinary tracts of certain animal species. All amphibians, birds, reptiles, and monotremes possess this orifice, from which they excrete both urine and feces, unlike placental mammals, which possess two (or three) separate orifices for evacuation.

The cloacal region is also often associated with a secretory organ, the cloacal gland, which has been implicated in the scent marking behavior of some reptiles, amphibians and monotremes.

The word comes from Latin, and means sewer. This was derived from cluō which meant "cleanse". See the Wiktionary article for more information.

In birds the cloaca is also referred to as the vent, and among falconers the word vent is also a verb meaning "to defecate". Excretory systems with analogous purpose in certain invertebrates are also sometimes referred to as "cloacae".

Birds also reproduce with this organ; this is known as a cloacal kiss. Birds that mate using this method touch their cloacae together, in some species for only a few seconds, sufficient time for sperm to be transferred from the male to the female. The reproductive system must be re-engorged prior to the mating season of each species. Such regeneration usually takes about a month. Birds generally produce one batch of eggs per year, but they will produce another if the first is taken away. For some birds, such as ostriches, cassowaries, kiwis, geese, and some species of swans and ducks, the males do not use the cloaca for reproduction but have a phallus. In those, the penis helps ensure that water does not wash away the male's sperm during copulation.

Wim Delvoye (born 1965 in Wervik, West Flanders) is a Belgian neo-conceptual artist known for his inventive and often shocking projects. Much of his work is focused on the body. He repeatedly links the attractive with the repulsive, creating work that holds within it inherent contradictions- one does not know whether to stare, be seduced, or to look away. As Robert Enright wrote in Border Crossings, "Delvoye is involved in a way of making art that reorients our understanding of how beauty can be created." Wim Delvoye has an eclectic oeuvre, exposing his interest in a range of themes, from bodily function, to the Catholic Church, and numerous subjects in between. He lives and works in Belgium, but recently moved to China after a court of law judged his pig tattoo art projects illegal.

Wim Delvoye was raised in Wervik, a small town in West Flanders, Belgium. Though he did not have a religious upbringing, Delvoye was influenced by the Roman Catholic society in which he lived, in particular the religion’s reverence of symbols. In a conversation with Michaël Amy of the New York Times, Delvoye stated, "I have vivid memories of crowds marching behind a single statue as well as of people kneeling in front of painted and carved altarpieces…Although I was barely aware of the ideas lurking behind these types of images, I soon understood that paintings and sculptures were of great importance." Delvoye’s artistic career would later be marked by his ability to manipulate objects.